Intel introduced a line of Pentium 4 desktop chips Sunday that contain 2MB of secondary cache, twice as much as current Pentium 4s, as well as technology from its notebook line that's designed to cut power consumption. Larger caches, a pool of memory located on the processor, generally improve performance. The four chips included in the new 600 series of Pentium 4s range in speeds from 3GHz to 3.6GHz, and all of them feature an 800MHz bus. The top-of-the-line 660 Pentium 4 sells for $605 in quantities of 1,000, while the 630 sells for $224.